I am a big believer in the idea that engineers, real professionals, need to have a clear view of what kind of performance technologies deliver, and should never
ever view performance statements as a political statement. They may be right or wrong, but they aren't political. This includes both not writing a project that needs very high performance and reaching for a known-lower-performance tool, and also not reaching for the absolutely highest performance tool which generally comes with a price when you are orders of magnitude away from needing it.
Erlang/Elixir has plenty of performance for plenty of problems, but Go is definitely generally a cut above. And there's definitely another cut above Go in performance, it's not the fastest, and there's a cut below Erlang/Elixir as well because they're generally faster than the dynamic scripting languages. And even the dynamic scripting languages are often fast enough for plenty of loads themselves.